Today in history... last case marks the end of smallpox

A highly infectious disease which at one time killed millions of people around the world was diagnosed for the final time 40 years ago today.

On October 26th, 1977, a Somali hospital cook and health worker, Ali Maow Maalin, was diagnosed with smallpox. Though he didn’t know it at the time, his would be the last case of the naturally-occurring infectious disease, which had been fought with extensive vaccination campaigns throughout the 19th and 20th centuries.

In 1980 the World Health Organisation (WHO) officially declared the global eradication of smallpox, making it the first infectious disease to be wiped out through vaccination. In 1967, just 10 years before the last case, the WHO estimated that 15 million people around the world had contracted smallpox and two million died from it.

Smallpox came in two variants, known by the medical names of ‘Variola major’ and ‘Variola minor’. The latter was a less severe form of the disease, which killed only about 1% of those infected with it, but with Variola major the overall mortality rate was as high as 35%. Even those who survived could suffer long-term complications, with up to 85% left disfigured by smallpox scars, usually on their face, and others experiencing blindness and limb deformities due to arthritis ad osteomyelitis.

Smallpox had been around for a long, long time, since before the dawn of civilisation. The earliest physical evidence of the disease is probably the rash found on the mummified body of Egyptian Pharaoh Ramses V, but references to a disease, or ‘plague’, assumed to be smallpox appear in earlier ancient texts.

My the mid-18th century it was a major endemic disease almost everywhere in the world and in Europe it was the leading cause of death, killing an estimated 400,000 people each year and responsible for a third of all blindness. With medical care less effective and completely unavailable for the poor, up to 60% of those infected at that time would die from smallpox, the figure rising as high as 80% in children.

People who caught smallpox first developed a characteristic red rash, which later changed to closely-packed raised blisters filled with fluid and covering large areas of the body. Other symptoms were similar to flu, with a raised temperature, muscle pain, headache, nausea and vomiting. With no way to contain the highly infectious disease, outbreaks were common and spread quickly. In England the disease was initially called the ‘red plague’, from the vivid colour of the initial rash, or simply ‘the pox’. Its later name of ‘smallpox’ was to distinguish it from another infectious disease, syphilis, which was called ‘the great pox’.

Smallpox is thought to have originated in Africa and spread throughout the world through the increased movement of people. For example, it was unknown in America before European settlers moved there, taking smallpox with them, and when it hit the native populations of these countries, who had built up no immunity, smallpox proved devastating.

It was English physician Edward Jenner (1749-1823) who pioneered a smallpox vaccine – the world’s first vaccine – and whose work is said to have saved more lives than that of any other human being before or since. It had been noted that people who had been infected with ‘cowpox’, a less far less dangerous disease caught from close proximity to cattle, seemed to be immune to smallpox.

Jenner hypothesised that the fluid from the blisters of someone with cowpox could be used to develop a vaccination against smallpox. He successfully tested his theory and went on to develop an effective smallpox vaccine. Over the decades that followed, vaccination became steadily more commonplace and by the 20th century, with further advances in medicine, it was being carried out on a large scale.

By the 1950s, vaccination was on a national scale in developed countries and outbreaks elsewhere in the world were fought by ‘ring vaccination’ – inoculating everyone living near an outbreak to prevent it spreading. The last major European outbreak was in Yugoslavia in 1972 and by 1975 the disease’s only remaining stronghold was in Africa.

Just two years later, Ali Maow Maalin’s isolated case of Variola minor smallpox would become the last known diagnosis of the infection. He was successfully treated and made a full recovery. Thankfully, smallpox is no more.

Next week will bring the shortest day of the year, on December 21st, and with the shortest day comes the longest night. Unfortunately, the long dark nights also mean that this time of year traditionally sees an increase in the number of burglaries.